The invention relates to a method for operating a continuous annealing line for the processing of a rolled good. The invention further relates to a control device for a continuous annealing line and a continuous annealing line.
After hot and cold rolling of a metallic strip, made of steel for example, the strip is subjected to heat treatment in order to set desired material properties in the strip. Industrially the heat treatment takes place for example in a continuous annealing line. In the continuous annealing line the strip is uncoiled and passes continuously through a furnace.
During the heat treatment in the continuous annealing line the aim, with a throughput which is as great as possible, is to refine the individual strips with quality which is as high and is as consistent as possible, both within one strip and also from strip to strip. The process parameters for the annealing process are set correspondingly for this purpose for each steel good. These are above all the strip speed and the temperature curve during annealing, i.e. the temperature of the individual heating and cooling sections within the annealing line. These process parameters are generally predetermined by the furnace manufacturer and/or by the operator and remain mostly unchanged for a steel good. When a new steel good is added, new process parameters are determined on the basis of empirical process data and experiments.
A method is known from EP 2 177 892 A1 in which, on the basis of measurement data of a steel sheet at a skin pass mill after a continuous annealing line, mechanical properties of the steel sheet are calculated and passed on to a user. The user can use the information about the calculated mechanical properties, by adapting the operating conditions of the steel production line for example. In such cases feedback control is undertaken, which only has an effect on new sections of the steel sheet.